CCR5 and HIV infectious disease: Sustained remission of HIV infection was achieved using stem-cell transplantation from donors homozygous for CCR5 null allele Δ32/Δ32, lacking functional expression of the CCR5 coreceptor and showing HIV resistance in two patients treated for acute myelogenous leukemia (Berlin patient) and refractory Hodgkin lymphoma (London patient) (206, 207).